Three people, including an elderly woman, were found dead inside their Watertown home Saturday morning, officials said. Police responded to a home on Boyd Street around 10 a.m. Saturday for a well-being check, according to the Middlesex District Attorney Marian Ryan. The three residents were found with apparent gunshot wounds. The elderly woman who was one of the victims lived on the upper floor of the unit, while a man and a woman lived together on the bottom floor, the DA said.